As the background art of this technical field, there is Japanese Unexamined Patent Application Publication No. 2012-59870 (Patent Literature 1). This publication describes a semiconductor device including: a first wide bandgap semiconductor region of a first conductivity type; a second wide bandgap semiconductor region of a second conductivity type formed so as to be sandwiched between the first semiconductor regions; and a plurality of third wide bandgap semiconductor regions of the second conductivity type, each of which is formed so as to be at least partially connected to the second semiconductor region and to be sandwiched between the first semiconductor regions. When the width of wide bandgap semiconductor layer of the first conductivity type is d, the interval between the third semiconductor regions is 2d×tan 18° or more.